The online laboratory: conducting experiments in a real labor market

Online labor markets have great potential as platforms for conducting experiments. They provide immediate access to a large and diverse subject pool, and allow researchers to control the experimental context. Online experiments, we show, can be just as valid—both internally and externally—as laboratory and field experiments, while often requiring far less money and time to design and conduct. To demonstrate their value, we use an online labor market to replicate three classic experiments. The first finds quantitative agreement between levels of cooperation in a prisoner’s dilemma played online and in the physical laboratory. The second shows—consistent with behavior in the traditional laboratory—that online subjects respond to priming by altering their choices. The third demonstrates that when an identical decision is framed differently, individuals reverse their choice, thus replicating a famed Tversky-Kahneman result. Then we conduct a field experiment showing that workers have upward-sloping labor supply curves. Finally, we analyze the challenges to online experiments, proposing methods to cope with the unique threats to validity in an online setting, and examining the conceptual issues surrounding the external validity of online results. We conclude by presenting our views on the potential role that online experiments can play within the social sciences, and then recommend software development priorities and best practices.     

“A profit table or a profit calculator?” A note on the design of Cournot oligopoly experiments

We report on an experiment conducted to evaluate the effects of varying the way in which market information is presented to participants in laboratory Cournot duopolies. We find that the most standard variations, which are the use of a profit table or a profit calculator, yield indistinguishable performance. However, the addition of a best-response option to the profit calculator tends to increase aggregate output to the Cournot level and decrease the incidence of tacit collusion.     

The effects of externalities and framing on bribery in a petty corruption experiment

Using a simple one-shot bribery game simulating petty corruption exchanges, we find evidence of a negative externality effect and a framing effect. When the losses suffered by third parties due to a bribe being offered and accepted are high and the game is presented as a petty corruption scenario instead of in abstract terms bribes are less likely to be offered. Higher negative externalities are also associated with less bribe acceptance. However, framing has no effect on bribe acceptance, indicating that the issue of artificiality may be of particular importance in bribery experiments.     

Professor Fisher and the quantity theory – a significant encounter

Abstract

Irving Fisher's encounter with the Quantity Theory of Money began in the 1890s, during the debate about bimetallism, and reached its high point in 1911 with the publication of The Purchasing Power of Money. His most important refinement of the theory, derived from his recognition of bank deposits as means of exchange, was to treat their out of equilibrium recursive interaction with inflation as integral to it. This treatment underlay both his 1920s work on the business cycle as a “dance of the dollar” and his advocacy of subjecting monetary policy to a legislated price stability rule, initially to be based on his “compensated dollar” scheme. Fisher's failure to recognise the onset of the Great Depression even as it was happening was directly related to his faith in the quantity theory's seeming implication that price level stability in and of itself guaranteed the continuation of prosperity, while his subsequent work on the debt deflation theory of great depressions initially failed to repair the damage that this failure did to his reputation, and to that of the quantity theory. In the 1930s Fisher nevertheless remained an active supporter of various schemes to reflate and then stabilise the price level. His subsequent influence on the quantity theory based Monetarist counter-revolution that began in the 1950s lay, directly, in its deployment of his analysis of expected inflation on nominal interest rates, and, indirectly, in its espousal of the case for subjecting monetary policy to a legislated rule.     

AIDS--mémoire

A czar was born when President Clinton named Kristine M. Gebbie to be his national AIDS policy coordinator. But a year later, under unrelenting fire from AIDS activists, Gebbie resigned. Her departure underscores the trouble that some activists have had shifting from the outsider's game to the insider's.     

Fragility of information cascades: an experimental study using elicited beliefs

This paper examines the occurrence and fragility of information cascades in two laboratory experiments. One group of low informed participants sequentially guess which of two states has been randomly chosen. In a matched pairs design, another group of high informed participants make similar guesses after having observed the guesses of the low informed participants. In the second experiment, participants’ beliefs about the chosen state are elicited. In equilibrium, low informed players who observe an established pattern of identical guesses herd without regard to their private information whereas high informed players always guess according to their private information. Equilibrium behavior implies that information cascades emerge in the group of low informed participants, the belief based solely on cascade guesses is stationary, and information cascades are systematically broken by high informed participants endowed with private information contradicting the cascade guesses. Experimental results show that the behavior of low informed participants is qualitatively in line with the equilibrium prediction. Information cascades often emerge in our experiments. The tendency of low informed participants to engage in cascade behavior increases with the number of identical guesses. Our main finding is that information cascades are not fragile. The behavior of high informed participants differs markedly from the equilibrium prediction. Only one-third of laboratory cascades are broken by high informed participants endowed with private information contradicting the cascade guesses. The relative frequency of cascade breaks is 15% for the situations where five or more identical guesses are observed. Participants’ elicited beliefs are strongly consistent with their own behavior and show that, unlike in equilibrium, the more cascade guesses participants observe the more they believe in the state favored by those guesses.     

Lost in translation – a revival of Wolfgang Stützel's Balances Mechanics

Wolfgang Stützel was a prominent German economist who coined a very special terminology in national accounting and in international economics. Therefore, it can be said that his contributions to economics got lost in translation. Especially, the Balances Mechanics approach and the paradox of competition are his biggest achievements in economic theory, but he never received international recognition. The objective of this paper is to pay tribute to his work by applying his analytical frameworks to the balance of payments crisis in the Eurozone and to the distributional impacts of austerity policy.     

Mika Tapani Widgrén

Obituary

Mika Tapani Widgrén     

Does context matter more for hypothetical than for actual contributions? Evidence from a natural field experiment

We investigated the importance of the social context for people’s voluntary contributions to a national park in Costa Rica, using a natural field experiment. Some subjects make actual contributions while others state their hypothetical contribution. Both the degree of anonymity and information provided about the contributions of others influence subject contributions in the hypothesized direction. We found a substantial hypothetical bias with regard to the amount contributed. However, the influence of the social contexts is about the same when the subjects make actual monetary contributions as when they state their hypothetical contributions. Our results have important implications for validity testing of stated preference methods: a comparison between hypothetical and actual behavior should be done for a given social context.      

Competition and innovation: an experimental investigation

The paper analyzes the effects of more intense competition on firms’ investments in process innovations. More intense competition corresponds to an increase in the number of firms or a switch from Cournot to Bertrand competition. We carry out experiments for two-stage games, where R&D investment choices are followed by product market competition. An increase in the number of firms from two to four reduces investments, whereas a switch from Cournot to Bertrand increases investments, even though theory predicts a negative effect in the four-player case. The results arise both in treatments in which both stages are implemented and in treatments in which only one stage is implemented. However, the positive effect of moving from Cournot to Bertrand competition is more pronounced in the former case.     

An experimental analysis of team production in networks

Experimental and empirical evidence highlights the role of networks on social outcomes. This paper tests the properties of exogenously fixed networks in team production. Subjects make the same decisions in a team work environment under four different organizational networks: the line, the circle, the star, and the complete network. In all the networks, links make information available to neighbors. This design allows us to analyze decisions across networks and a variety of subject types in a standard linear team production game. Contribution levels differ significantly across networks and the star is the most efficient incomplete network. Moreover, our results suggest that subjects act as conditional cooperators with respect to the information received from the network.     

A model of boundedly rational “neuro” agents

We consider a model in which each agent in a population chooses one of two options. Each agent does not know what the available options are and can choose an option only after observing another agent who has already chosen that option. In addition, the agents’ preferences over the two options are correlated. An agent can either imitate an observed agent or wait until he meets two agents who made different choices, in which case he can compare their choices and choose accordingly. A novel feature of the model is that agents observe not only the choices made by others, but also some information about the process that led them to those choices. We study two cases: In the first, an agent notes whether the observed agent imitated others or whether he actually compared the available alternatives. In the second, an agent notes whether the observed agent’s decision was hasty or not. It is shown that in equilibrium the probability of making a mistake is higher in the second case and that the existence of these nonstandard “neuro” observations systematically biases the equilibrium distribution of choices.     

A comparative statics analysis of punishment in public-good experiments

This paper provides a comparative-statics analysis of punishment in public-good experiments. We vary the effectiveness of punishment, that is, the factor by which punishment reduces the punished player’s income. The data show that contributions increase monotonically in punishment effectiveness. High effectiveness leads to near complete cooperation and welfare improvements. Below a certain threshold, however, punishment cannot prevent the decay of cooperation. In these cases, punishment opportunities reduce welfare. The results suggest that the experimenter’s choice of the punishment effectiveness is of great importance for the experimental outcome.

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Electronic Supplementary Material  The online version of this article () contains supplementary material, which is available to authorized users.      

The impact of downward social information on contribution decisions

In this paper we study the effect of downward social information in contribution decisions to fund public goods. We describe the results of a field experiment run in conjunction with the fundraising campaigns of a public radio station. Renewing members are presented with social information (information about another donor’s contribution) which is either above or below their previous (last year’s) contribution. We find that respondents change their contribution in the direction of the social information; increasing their contribution when the social information is above their previous contribution, and decreasing their contribution when the social information is below. We hypothesize about the psychological motivations that may cause the results and test these hypotheses by comparing the relative size of the upward and downward shifts. These results improve our understanding of cooperation in public good provision and suggest differential costs and benefits to fundraisers in providing social information.      

Classification of natural language messages using a coordination game

The role of natural language communication in economic exchange has been the focus of substantial experimental analysis. Recently, scholars have taken the important step of investigating whether certain types of communication (e.g., promises) might affect decisions differently than other types of communication. This requires classifying natural language messages. Unfortunately, no broadly-accepted method is available for this purpose. We here describe a coordination game for classification of natural language messages. The game is similar in spirit to the “ESP” game that has proven successful for the classification of tens of millions of internet images. We compare our approach to self-classification as well as to classifications based on a standard content analysis. We argue that our classification game has advantages over those alternative approaches, and that these advantages might stem from the salient rewards earned by our game’s participants.